* Re: Writing an amount of data less than capacity at random to offsets from whole address range
2014-04-14 12:40 Writing an amount of data less than capacity at random to offsets from whole address range Nikolaus Jeremic
@ 2014-04-14 20:11 ` Jens Axboe
2014-04-28 17:15 ` Nikolaus Jeremic
0 siblings, 1 reply; 4+ messages in thread
From: Jens Axboe @ 2014-04-14 20:11 UTC (permalink / raw)
To: Nikolaus Jeremic, fio
[-- Attachment #1: Type: text/plain, Size: 1206 bytes --]
On 04/14/2014 06:40 AM, Nikolaus Jeremic wrote:
> Hello,
>
> how can I nudge fio to write a certain amount of data (less than
> capacity of block device) to randomly generated offsets covering the
> whole address space of a block device (e.g. MD RAID device)?
>
> Using the size parameter yields offsets from 0 to size (thus, not
> covering the whole address range). Using a time based job leads to the
> desired result, but I would like two write a defined amount of data. I
> have already tried this with fio 2.0.14, 2.1.6.1, 2.1.17, and 2.1.18
> without success. I am using Gentoo Linux with kernel 3.13.6 and libaio
> 0.3.109. The job description looks as follows:
Fio doesn't currently support that. Can you try the attached? It adds an
option to separately define an io limit, io_limit. If io_limit is not
set, size= behaves as it did before: if you don't give a size, size is
defined by the files added. With this patch, if you do
filename=/dev/md9
size=40g
fio would read 40g between 0..40G
If you do:
filename=/dev/md9
fio would access the entire device.
If you do:
filename=/dev/md9
io_limit=10g
fio would access the entire device, quit when 10G of IO was done. Etc.
--
Jens Axboe
[-- Attachment #2: fio-io-limit.patch --]
[-- Type: text/x-patch, Size: 4328 bytes --]
diff --git a/backend.c b/backend.c
index 62bca29194ed..47c4d32e8862 100644
--- a/backend.c
+++ b/backend.c
@@ -641,7 +641,7 @@ static unsigned int exceeds_number_ios(struct thread_data *td)
static int io_bytes_exceeded(struct thread_data *td)
{
- unsigned long long bytes;
+ unsigned long long bytes, limit;
if (td_rw(td))
bytes = td->this_io_bytes[DDIR_READ] + td->this_io_bytes[DDIR_WRITE];
@@ -652,7 +652,12 @@ static int io_bytes_exceeded(struct thread_data *td)
else
bytes = td->this_io_bytes[DDIR_TRIM];
- return bytes >= td->o.size || exceeds_number_ios(td);
+ if (td->o.io_limit)
+ limit = td->o.io_limit;
+ else
+ limit = td->o.size;
+
+ return bytes >= limit || exceeds_number_ios(td);
}
/*
@@ -1137,6 +1142,8 @@ static int switch_ioscheduler(struct thread_data *td)
static int keep_running(struct thread_data *td)
{
+ unsigned long long limit;
+
if (td->done)
return 0;
if (td->o.time_based)
@@ -1148,14 +1155,19 @@ static int keep_running(struct thread_data *td)
if (exceeds_number_ios(td))
return 0;
- if (td->o.size != -1ULL && ddir_rw_sum(td->io_bytes) < td->o.size) {
+ if (td->o.io_limit)
+ limit = td->o.io_limit;
+ else
+ limit = td->o.size;
+
+ if (limit != -1ULL && ddir_rw_sum(td->io_bytes) < limit) {
uint64_t diff;
/*
* If the difference is less than the minimum IO size, we
* are done.
*/
- diff = td->o.size - ddir_rw_sum(td->io_bytes);
+ diff = limit - ddir_rw_sum(td->io_bytes);
if (diff < td_max_bs(td))
return 0;
diff --git a/cconv.c b/cconv.c
index 5b9c3be2590c..a87f431c8c92 100644
--- a/cconv.c
+++ b/cconv.c
@@ -77,6 +77,7 @@ void convert_thread_options_to_cpu(struct thread_options *o,
o->iodepth_batch = le32_to_cpu(top->iodepth_batch);
o->iodepth_batch_complete = le32_to_cpu(top->iodepth_batch_complete);
o->size = le64_to_cpu(top->size);
+ o->io_limit = le64_to_cpu(top->io_limit);
o->size_percent = le32_to_cpu(top->size_percent);
o->fill_device = le32_to_cpu(top->fill_device);
o->file_append = le32_to_cpu(top->file_append);
@@ -425,6 +426,7 @@ void convert_thread_options_to_net(struct thread_options_pack *top,
memcpy(top->buffer_pattern, o->buffer_pattern, MAX_PATTERN_SIZE);
top->size = __cpu_to_le64(o->size);
+ top->io_limit = __cpu_to_le64(o->io_limit);
top->verify_backlog = __cpu_to_le64(o->verify_backlog);
top->start_delay = __cpu_to_le64(o->start_delay);
top->start_delay_high = __cpu_to_le64(o->start_delay_high);
diff --git a/filesetup.c b/filesetup.c
index 490f0fc2101b..b614dbacabaa 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -939,8 +939,12 @@ int setup_files(struct thread_data *td)
* iolog already set the total io size, if we read back
* stored entries.
*/
- if (!o->read_iolog_file)
- td->total_io_size = o->size * o->loops;
+ if (!o->read_iolog_file) {
+ if (o->io_limit)
+ td->total_io_size = o->io_limit * o->loops;
+ else
+ td->total_io_size = o->size * o->loops;
+ }
done:
if (o->create_only)
diff --git a/options.c b/options.c
index 50af7b499f4b..163c5fc92985 100644
--- a/options.c
+++ b/options.c
@@ -1595,6 +1595,15 @@ struct fio_option fio_options[FIO_MAX_OPTS] = {
.group = FIO_OPT_G_INVALID,
},
{
+ .name = "io_limit",
+ .lname = "IO Limit",
+ .type = FIO_OPT_STR_VAL,
+ .off1 = td_var_offset(io_limit),
+ .interval = 1024 * 1024,
+ .category = FIO_OPT_C_IO,
+ .group = FIO_OPT_G_INVALID,
+ },
+ {
.name = "fill_device",
.lname = "Fill device",
.alias = "fill_fs",
diff --git a/server.h b/server.h
index 2958e7306c3e..4f09f2848b93 100644
--- a/server.h
+++ b/server.h
@@ -38,7 +38,7 @@ struct fio_net_cmd_reply {
};
enum {
- FIO_SERVER_VER = 33,
+ FIO_SERVER_VER = 34,
FIO_SERVER_MAX_FRAGMENT_PDU = 1024,
FIO_SERVER_MAX_CMD_MB = 2048,
diff --git a/thread_options.h b/thread_options.h
index 46421205cdf9..41b6e54e7372 100644
--- a/thread_options.h
+++ b/thread_options.h
@@ -52,6 +52,7 @@ struct thread_options {
unsigned int iodepth_batch_complete;
unsigned long long size;
+ unsigned long long io_limit;
unsigned int size_percent;
unsigned int fill_device;
unsigned int file_append;
@@ -280,6 +281,7 @@ struct thread_options_pack {
uint32_t iodepth_batch_complete;
uint64_t size;
+ uint64_t io_limit;
uint32_t size_percent;
uint32_t fill_device;
uint32_t file_append;
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